article: Long ago, there was an interesting man called Effendi  , He had a good sense of humour. One day he played a joke on the Prime Minister  . He said that the Minister would die the next day. Really the next day, the Minister fell off the horse and died. When the king learned this, he got angry and sent his men to cat ch Effendi at once.
  When Effendi was in front of the King, the king shouted angrily, "Effendi, since   you know when my Minister would die, you must know the date of your own death. Say it out, or you will die today."Effendi looked at the king for a while, he answered, "But how can I know? I'll die two days earlier than you."Because the king was afraid if he killed Effendi, he himself would die after that. He thought he must keep Effendi alive as long as he could, so he let Effendi go.
question: The king let Effendi go because   _  .
options: he hoped to live a long life he was afraid of Effendi he didn't believe Effendi he knew he would die two days later